1. Field of the Invention
This invention relates to a disk device having disks as recording media.
2. Description of the Related Art
In recent years, disk devices, such as magnetic disk devices, optical disk devices, etc., have been widely used as external recording devices of computers and image recording devices.
A magnetic disk device as an example of a disk device generally has a case in the form of a rectangular box. The case contains magnetic disks for use as magnetic recording media, a spindle motor, magnetic heads, and a head actuator. The spindle motor serves as drive means that supports and rotates the disks. The magnetic heads are used to write and read information to and from the disks. The head actuator supports the heads for movement with respect to the disks. Further, the case contains a voice coil motor, a substrate unit, etc. The voice coil motor rocks and positions the head actuator. The substrate unit has a head IC and the like.
A printed circuit board for controlling the respective operations of the spindle motor, voice coil motor, and magnetic heads through the substrate unit is screwed to the outer surface of the case. An interface (I/F) connector for connecting the magnetic disk device to an external device is soldered to an end portion of the circuit board.
In the magnetic disk device constructed in this manner, the pin arrangement of the interface connector and the like must be changed depending on the specifications of the external device to be connected. For example, the input side must be allotted to a predetermined pin of the interface connector for one external device, and the output side to the predetermined pin of the connector for another external device.
According to an information recording device described in Jpn. Pat. Appln. KOKAI Publication No. 7-281838, for example, a single common interface connector is used, and an IC for control that is connected to this interface connector is provided with an input/output circuit so that the properties of external terminals of the control IC can be selected by a plurality of selectors. Thus, the interface specifications can be changed in the control IC.
Recently, miniaturization of magnetic disk devices has been advanced to facilitate their use as recording devices of more varied electronic apparatuses, especially smaller-sized electronic apparatuses. In a magnetic disk device that uses disks with a diameter of 1 inch or more, for example, the printed circuit board overlapped on the surface of the case can be made smaller than the case surface in area. In a magnetic disk device that uses disks with a diameter of less than 1 inch, however, the printed circuit board must be reduced with the miniaturization of the case. Accordingly, an installation space on the printed circuit board lessens, so that a plurality of electronic components cannot be mounted on it with ease. The interface connector for connecting the magnetic disk device and the external device, in particular, is relatively tall and large-sized, so that it cannot be readily mounted on the circuit board. Further, it constitutes a hindrance to the reduction in overall thickness of the magnetic disk device including the printed circuit board. Likewise, it is necessary to miniaturize the control IC and other electronic components that are mounted on the printed circuit board. If the input/output circuit, selectors, etc. are incorporated in the control IC in the aforesaid manner, however, the circuit configuration is complicated, and the miniaturization of the IC is not easy.